CN114807685B - Preparation method of directionally arranged graphene reinforced aluminum matrix composite - Google Patents

Abstract

The invention relates to a preparation method of an oriented graphene-reinforced aluminum-based composite material. In view of the uneven dispersion of graphene in an aluminum matrix, and it is difficult to form a firm interface with the aluminum matrix, aluminum is used as the matrix and graphene is used as the reinforcement. After ball milling, ultrasonic dispersion, powder mixing, drying, vibration pressurization, and plasma discharge sintering, aligned graphene-reinforced aluminum matrix composites were prepared. This preparation method has advanced technology, accurate and detailed data, and strict procedures. The prepared oriented graphene reinforced aluminum matrix composite material has a hardness of 97.7HV and a tensile strength of 189MPa. The graphene is oriented in the aluminum matrix and has a certain relationship with the aluminum matrix. Good interfacial bonding is an advanced preparation method for aligning graphene reinforced aluminum matrix composites.

Description

A preparation method of aligned graphene reinforced aluminum matrix composites

technical field

The invention relates to a method for preparing an aligned graphene-reinforced aluminum-based composite material, which belongs to the technical field of non-ferrous metal composite material preparation.

Background technique

Graphene has excellent mechanical properties and is currently a reinforcement for preparing metal matrix composites. Adding graphene to the aluminum matrix can improve the mechanical properties of aluminum and aluminum alloys, thereby broadening the application range of aluminum and creating favorable conditions for the industrial development of aluminum matrix composites. However, graphene itself is easy to agglomerate, and it is difficult to disperse uniformly in aluminum. Moreover, due to the unique two-dimensional structure, the performance of graphene has strong anisotropy, and it is prone to large performance differences. Therefore, achieving uniform dispersion and orientation of graphene is conducive to improving the performance of graphene-reinforced aluminum matrix composites.

At present, graphene-reinforced aluminum matrix composites are mainly prepared by hot pressing and sintering. This preparation method takes a long time, has low efficiency, and the prepared samples have many internal defects; another common method is the melt-stirring casting method. The forming process of the method is complex, the temperature in the process is difficult to control accurately, and graphene is prone to agglomeration and high temperature burning; in contrast, vibration plasma sintering has many potential advantages for the preparation of graphene-reinforced aluminum matrix composites. under scientific research.

How to uniformly disperse graphene into aluminum matrix and form a good interfacial bond between graphene and aluminum matrix without destroying the microstructure of graphene is a technical problem in the preparation of graphene-reinforced aluminum matrix composites. At the same time, the introduction of aligned graphene can effectively enhance the strength of the composite material and better control the material properties. At present, aligned graphene-reinforced aluminum matrix composites are still in the research stage, and its process technology needs to be further improved.

Contents of the invention

purpose of invention

The purpose of the present invention is to prepare aligned graphene-reinforced aluminum-based composite materials with aluminum as the matrix and graphene as the reinforcement against the status of the background technology.

Technical solutions

The chemical substance material that the present invention uses is: graphene, aluminum, dehydrated alcohol, deionized water, argon gas, and its combined preparation consumption is as follows: take gram, milliliter, centimeter as unit ^of measurement

Graphene: C solid powder 1g±0.001g

Spherical aluminum powder: Al solid powder 100g±0.001g

Absolute ethanol: C₂h₅Oh Liquid liquid 2000mL±10mL

Deionized water: H ₂ O liquid liquid 1000mL±5mL

Argon: Ar gaseous gas 2000000cm ³ ±100cm ³

The preparation method is as follows:

1) Ball milling

Weigh 99.5g of spherical aluminum powder, measure 500mL of absolute ethanol, and add them into the ball milling tank of the planetary ball mill; then, close the mouth of the tank, use a vacuum pump to extract the air in the ball milling tank, and simultaneously feed argon into the ball milling tank for continuous The time is 2 minutes; then, start the planetary ball mill for ball milling, the ball weight is 2000g, the ball diameter is 6mm, the ball milling speed is 200r/min, and the ball milling time is 6h; in order to avoid cold welding, every ball mill is 30min, and the ball mill is suspended for 30min To lower the temperature, the aluminum powder slurry is thus prepared; then, the aluminum powder slurry and the grinding balls are separated with a sample sieve;

2) Ultrasonic dispersion

Weigh 0.5g±0.001g of graphene, measure 300mL of deionized water, add it into a beaker with a capacity of 500mL, and rotate and stir with a glass rod; then, put the beaker into an ultrasonic oscillator for ultrasonic dispersion, and the oscillation frequency is 720W , the dispersion time is 2h, thus the graphene dispersion is prepared;

3) Mix powder

Add the aluminum powder slurry and the graphene dispersion into a beaker with a capacity of 1000mL for mechanical stirring, the stirring rate is 300r/min, and the stirring time is 50min, thus preparing the mixed slurry;

4) drying

Put the beaker containing the mixed slurry into a vacuum drying oven for drying, the drying temperature is 60°C, and the drying time is 24 hours, thereby preparing the mixed powder;

5) Vibration pressurization

Put the mixed powder into the graphite mold of the vibrating plasma sintering furnace, close the furnace door after fixing the mold, and pump out the air in the furnace cavity with a vacuum pump; then, start the pressurizing device and vibration device of the vibrating plasma sintering furnace, The mixed powder is vibrated and pressurized, the pressure is 50MPa, the vibration frequency is 10Hz, and the vibration time is 5min;

6) Plasma discharge sintering

Shut down the vibrating device of the vibrating plasma sintering furnace, and start the plasma discharge device to discharge and sinter the mixed powder in the graphite mold. The sintering temperature is 550°C, the sintering time is 10min, and the sintering heating rate is ≤100°C/min. The mixed powder in the graphite mold is sintered into an aligned graphene-reinforced aluminum matrix composite material; then, shut down the pressurization device and plasma discharge device of the vibration plasma sintering furnace, and cool the furnace body of the vibration plasma sintering furnace with cooling water; open Furnace door, take out the aligned graphene-reinforced aluminum matrix composite material in the graphite mold;

7) cleaning, cleaning

Clean the aligned graphene-reinforced aluminum matrix composite with absolute ethanol, and dry it after cleaning;

8) Detection, analysis, characterization

Detect, analyze, and characterize the morphology, structure, and mechanical properties of aligned graphene-reinforced aluminum matrix composites;

Use a metallographic analyzer to analyze the metallographic structure;

Hardness analysis with Vickers hardness tester;

Tensile strength analysis with electronic universal testing machine;

Conclusion: The hardness of the oriented graphene reinforced aluminum matrix composite reaches 97.7HV, and the tensile strength reaches 189MPa. The graphene is oriented in the aluminum matrix and has a good interface with the aluminum matrix.

Beneficial effect

Compared with the background technology, the present invention has obvious advances. It aims at the situation that graphene is not uniformly dispersed in the aluminum matrix, and it is difficult to form a firm interface with the aluminum matrix. Aluminum is used as the matrix and graphene is used as a reinforcement. After ball milling, Aligned graphene-reinforced aluminum matrix composites were prepared by ultrasonic dispersion, powder mixing, drying, vibration pressing, and plasma discharge sintering. This preparation method has advanced technology, accurate and detailed data, and strict procedures. The prepared oriented graphene-reinforced aluminum matrix composite has a hardness of 97.7HV and a tensile strength of 189MPa. Good interfacial bonding is an advanced method for preparing aligned graphene-reinforced aluminum matrix composites.

Description of drawings

Figure 1 is a state diagram of vibration pressurization and plasma discharge sintering.

Fig. 2 is a microstructure diagram of aligned graphene-reinforced aluminum matrix composites.

Figure 3 is a diagram of the tensile properties of aligned graphene reinforced aluminum matrix composites.

As shown in the figure, the list of reference signs is as follows:

1-PLC control cabinet, 2-control cabinet switch, 3-alarm, 4-pressure control knob, 5-temperature control knob, 6-time control knob, 7-vibration frequency control knob, 8-signal line, 9-cooling Water inlet, 10-cooling water outlet, 11-vacuum pump, 12-vacuumizing valve, 13-furnace body of vibration plasma sintering furnace, 14-upper hydraulic station, 15-lower hydraulic station, 16-conical head, 17-pressure Rod, 18-high-frequency vibrator, 19-resonator, 20-graphite mold of vibration plasma sintering furnace, 21-temperature measuring hole, 22-thermocouple, 23-vacuum breaking valve, 24-vacuum gauge, 25-positive copper Line row, 26-negative copper wire row, 27-high frequency power supply positive pole, 28-high frequency power supply negative pole, 29-power cabinet switch, 30-voltage control knob, 31-high frequency power supply cabinet.

Detailed ways

The present invention will be further described below in conjunction with accompanying drawing:

As shown in Fig. 1, it is a state diagram of vibration pressurization and plasma discharge sintering; the complete set of equipment includes a vibration plasma sintering furnace, a PLC control cabinet 1, a vacuum pump 11, a vacuum valve 12, a vacuum breaking valve 23, and a vacuum gauge 24;

The furnace body 13 of the vibration plasma sintering furnace is respectively provided with a cooling water inlet 9 and a cooling water outlet 10;

The graphite mold 20 of the vibration plasma sintering furnace is provided with a temperature measuring hole 21; a thermocouple 22 is inserted in the temperature measuring hole 21;

The pressurizing device of the vibration plasma sintering furnace includes an upper hydraulic station 14, a lower hydraulic station 15, two conical heads 16, and two pressure rods 17;

The vibrating device of the vibrating plasma sintering furnace includes a high-frequency vibrator 18 and a resonator 19;

The plasma discharge device of the vibrating plasma sintering furnace includes a positive electrode copper wire row 25, a negative electrode copper wire row 26, a high frequency power supply positive electrode 27, a high frequency power supply negative electrode 28, and a high frequency power supply cabinet 31; the high frequency power supply cabinet 31 is respectively equipped with a power supply cabinet Switch 29, voltage control knob 30;

The PLC control cabinet 1 is respectively connected to the pressurizing device and the vibration device of the vibrating plasma sintering furnace through the signal line 8; the PLC control cabinet 1 is respectively provided with a control cabinet switch 2, an alarm 3, a pressure control knob 4, a temperature control knob 5, Time control knob 6, vibration frequency control knob 7;

The vacuum pump 11 communicates with the furnace chamber of the vibrating plasma sintering furnace through the vacuum valve 12;

The vacuum breaking valve 23 and the vacuum gauge 24 are all communicated with the furnace cavity of the vibrating plasma sintering furnace;

In the vibration pressurization process, the mixed powder is put into the graphite mold 20 of the vibratory plasma sintering furnace; then, close the furnace door, open the vacuum valve 12, start the vacuum pump 11, and use the vacuum pump 11 to extract the air in the furnace cavity, and the vacuum degree is determined by Vacuum gauge 24 monitoring; then, start the PLC control cabinet 1 through the control cabinet switch 2, start the vibration of the upper hydraulic station 14 and the lower hydraulic station 15 through the pressure control knob 4, and start the high-frequency vibrator 18 and resonance through the vibration frequency control knob 7 at the same time device 19; the upper hydraulic station 14 and the lower hydraulic station 15 respectively push the two pressure rods 17 to move towards each other, and the two pressure rods 17 respectively drive the two conical heads 16 to move towards each other, and the two conical heads 16 jointly move the graphite mould. The mixed powder is pressed; the high-frequency vibrator 18 and the resonator 19 perform high-frequency vibration together, and drive the mixed powder in the graphite mold to perform high-frequency vibration;

During the plasma discharge sintering process, the high-frequency vibrator 18 and the resonator 19 are shut down through the vibration frequency control knob 7, and the high-frequency power supply cabinet 31 is started through the power supply cabinet switch 29, the output voltage is set through the voltage control knob 30, and the temperature control knob is used to set the output voltage. 5 and time control knob 6 to set the sintering temperature and sintering time, the current output by the high-frequency power supply cabinet 31 flows through the positive electrode 27 of the high-frequency power supply, the positive electrode copper wire row 25, the graphite mold 20 of the vibration plasma sintering furnace, and the negative electrode copper wire row 26 , high-frequency power supply negative pole 28, and when flowing through the graphite mold 20 of the vibration plasma sintering furnace, the mixed powder in the graphite mold 20 is sintered, and the sintering temperature is monitored by the thermocouple 22, thus the mixed powder in the graphite mold 20 is sintered Arrange graphene-reinforced aluminum-based composite materials in an oriented manner; then, shut down the vibration upper hydraulic station 14 and lower hydraulic station 15 through the pressure control knob 4, shut down the high-frequency power supply cabinet 31 through the power cabinet switch 29, and pass through the cooling water inlet 9 Enter the cooling water, the cooling water cools down the furnace body 13 of the vibrating plasma sintering furnace and discharges through the cooling water outlet 10; then, turn off the vacuum pump 11, close the vacuum valve 12, open the vacuum breaking valve 23, and let the air flow into the vibrating plasma The furnace chamber of the sintering furnace is opened, and the aligned graphene-reinforced aluminum matrix composite material in the graphite mold 20 is taken out.

As shown in Figure 2, it is the microstructure diagram of the aligned graphene-reinforced aluminum matrix composite material; as shown in the figure, the structure of the material is dense, the graphene is evenly distributed, and it shows the regularity of the alignment.

As shown in Fig. 3, it is a diagram of tensile properties of aligned graphene reinforced aluminum matrix composites. As shown in the figure, the tensile strength of aligned graphene-reinforced aluminum matrix composite reaches 189MPa.

Although the specific embodiments of the present invention have been described above, those skilled in the art should understand that these are only examples, and the protection scope of the present invention is defined by the appended claims. Those skilled in the art can make various changes or modifications to these embodiments without departing from the principle and essence of the present invention, but these changes and modifications all fall within the protection scope of the present invention.

Claims (1)

1. A preparation method for aligned graphene-reinforced aluminum matrix composites, characterized in that: The chemical substances and materials used are: graphene, aluminum, absolute ethanol, deionized water, argon, and the preparation dosage of the combination is as follows: the unit ^of measurement is gram, milliliter, and centimeter Graphene: C solid powder 1g±0.001g Spherical aluminum powder: Al solid powder 100g±0.001g Absolute ethanol: C₂h₅Oh Liquid liquid 2000mL±10mL Deionized water: H ₂ O liquid liquid 1000mL±5mL Argon: Ar gaseous gas 2000000cm ³ ±100cm ³ The preparation method is as follows: 1) Ball milling Weigh 99.5g of spherical aluminum powder, measure 500mL of absolute ethanol, and add them into the ball milling tank of the planetary ball mill; then, close the mouth of the tank, use a vacuum pump to extract the air in the ball milling tank, and simultaneously feed argon into the ball milling tank for continuous The time is 2 minutes; then, start the planetary ball mill for ball milling, the ball weight is 2000g, the ball diameter is 6mm, the ball milling speed is 200r/min, and the ball milling time is 6h; in order to avoid cold welding, every ball mill is 30min, and the ball mill is suspended for 30min To lower the temperature, the aluminum powder slurry is thus prepared; then, the aluminum powder slurry and the grinding balls are separated with a sample sieve; 2) Ultrasonic dispersion Weigh 0.5g±0.001g of graphene, measure 300mL of deionized water, add it into a beaker with a capacity of 500mL, and rotate and stir with a glass rod; then, put the beaker into an ultrasonic oscillator for ultrasonic dispersion, and the oscillation frequency is 720W , the dispersion time is 2h, thus the graphene dispersion is prepared; 3) Mix powder Add the aluminum powder slurry and the graphene dispersion into a beaker with a capacity of 1000mL for mechanical stirring, the stirring rate is 300r/min, and the stirring time is 50min, thus preparing the mixed slurry; 4) drying Put the beaker containing the mixed slurry into a vacuum drying oven for drying, the drying temperature is 60°C, and the drying time is 24 hours, thereby preparing the mixed powder; 5) Vibration pressurization Put the mixed powder into the graphite mold of the vibrating plasma sintering furnace, close the furnace door after fixing the mold, and pump out the air in the furnace cavity with a vacuum pump; then, start the pressurizing device and vibration device of the vibrating plasma sintering furnace, The mixed powder is vibrated and pressurized, the pressure is 50MPa, the vibration frequency is 10Hz, and the vibration time is 5min; 6) Plasma discharge sintering Shut down the vibrating device of the vibrating plasma sintering furnace, and start the plasma discharge device to discharge and sinter the mixed powder in the graphite mold. The sintering temperature is 550°C, the sintering time is 10min, and the sintering heating rate is ≤100°C/min. The mixed powder in the graphite mold is sintered into an aligned graphene-reinforced aluminum matrix composite material; then, shut down the pressurization device and plasma discharge device of the vibration plasma sintering furnace, and cool the furnace body of the vibration plasma sintering furnace with cooling water; open Furnace door, take out the aligned graphene-reinforced aluminum matrix composite material in the graphite mold; 7) cleaning, cleaning Clean the aligned graphene-reinforced aluminum matrix composite with absolute ethanol, and dry it after cleaning; 8) Detection, analysis, characterization Detect, analyze, and characterize the morphology, structure, and mechanical properties of aligned graphene-reinforced aluminum matrix composites; Use a metallographic analyzer to analyze the metallographic structure; Hardness analysis with Vickers hardness tester; Tensile strength analysis with electronic universal testing machine; Conclusion: The hardness of the oriented graphene reinforced aluminum matrix composite reaches 97.7HV, and the tensile strength reaches 189MPa. The graphene is oriented in the aluminum matrix and has a good interface with the aluminum matrix.

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